Letu Ren wrote:
> Thanks for the patch.I back-ported your patch and tested in ArchLinux
> chroot. It still failed because the type of /proc/self/loginuid is uid_t
> not string.
Thanks for testing and reporting back.
> By the way, I accidentally created a new thread in the mailing list
> because I'm not familiar with `git send-email`.
That's not a problem; we can live with that.
But there's no need to follow up in private email; please always keep the
list in CC.
> I made some changes based on your patch and tested
> the patch under ArchLinux x86_64 chroot.
>
>
> * tests/test-getlogin.h (test_getlogin_result):
> According to the source code of glibc, the type of /proc/self/loginuid is
> uid_t, which is unsigned int.
>
> Signed-off-by: Letu Ren <fantasq...@gmail.com>
> ---
> tests/test-getlogin.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tests/test-getlogin.h b/tests/test-getlogin.h
> index 3489e3e03..b5ed8b572 100644
> --- a/tests/test-getlogin.h
> +++ b/tests/test-getlogin.h
> @@ -58,9 +58,9 @@ test_getlogin_result (const char *buf, int err)
> FILE *fp = fopen ("/proc/self/loginuid", "r");
> if (fp != NULL)
> {
> - char buf[3];
> + uid_t uid;
> loginuid_undefined =
> - (fread (buf, 1, 3, fp) == 2 && buf[0] == '-' && buf[1] == '1');
> + (fscanf (fp, "%u", &uid) == 1 && uid == (uid_t) -1);
> fclose (fp);
> }
I don't like the *scanf family of functions. For a simple parsing function
like strtoul(), I can understand for which inputs it behaves in which ways
(empty input? not integer syntax? leading minus sign? unsigned integer
overflow?); for fscanf there are just too many cases, I can't wrap my head
around.
So I'm committing this instead.
2022-06-19 Bruno Haible <br...@clisp.org>
getlogin, getlogin_r tests: Really avoid test failure.
Reported by Letu Ren <fantasq...@gmail.com> in
<https://lists.gnu.org/archive/html/bug-gnulib/2022-06/msg00037.html>.
* tests/test-getlogin.h (test_getlogin_result): Parse the contents of
/proc/self/loginuid as an unsigned integer.
diff --git a/tests/test-getlogin.h b/tests/test-getlogin.h
index 3489e3e03d..fcc7741f12 100644
--- a/tests/test-getlogin.h
+++ b/tests/test-getlogin.h
@@ -51,16 +51,25 @@ test_getlogin_result (const char *buf, int err)
#if defined __linux__
/* On Linux, it is possible to set up a chroot environment in such a way
that stdin is connected to a tty and nervertheless /proc/self/loginuid
- contains "-1". In this situation, getlogin() and getlogin_r() fail;
- this is expected. */
+ contains the value (uid_t)(-1). In this situation, getlogin() and
+ getlogin_r() fail; this is expected. */
bool loginuid_undefined = false;
- /* Does the special file /proc/self/loginuid contain "-1"? */
+ /* Does the special file /proc/self/loginuid contain the value
+ (uid_t)(-1)? */
FILE *fp = fopen ("/proc/self/loginuid", "r");
if (fp != NULL)
{
- char buf[3];
- loginuid_undefined =
- (fread (buf, 1, 3, fp) == 2 && buf[0] == '-' && buf[1] == '1');
+ char buf[21];
+ size_t n = fread (buf, 1, sizeof buf, fp);
+ if (n > 0 && n < sizeof buf)
+ {
+ buf[n] = '\0';
+ errno = 0;
+ char *endptr;
+ unsigned long value = strtoul (buf, &endptr, 10);
+ if (*endptr == '\0' && errno == 0)
+ loginuid_undefined = ((uid_t) value == (uid_t)(-1));
+ }
fclose (fp);
}
if (loginuid_undefined)
